A study was performed to assess the feasibility of using a focused CO2 laser beam to cut the gage of a hard-rock tunnel being excavated by a continuous tunnel-boring machine. Laser rock-kerfing tests were conducted on isolated samples of granite, diabase and quartzite rock with a Navy-owned electric-discharge CO2 laser located at the United Aircraft Research Laboratories. The tests were performed to verify previously made extrapolations which were used to predict full-scale power requirements for the laser gage-kerfing concept. Laser powers and kerfing speeds were extended from previously tested maximum values of 5 kW and 21.2 cm/sec to 16.5 kW and 125 cm/sec. In addition, the test program included a comparison of the use of 50.8 cm-focal-length spherical and cylindrical focusing mirrors.

  • Corporate Authors:

    United Aircraft Corporation

    Research Laboratories
    East Hartford, CT  United States 

    Federal Railroad Administration

    Office of Research and Development, 1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Jurewicz, B R
    • Greenwald, L E
    • Brown, C O
  • Publication Date: 1974-11

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 166 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00090403
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FRA-ORD&D 75-20 Final Rpt., UARL-N971543-11
  • Contract Numbers: DOT-FR-20021
  • Files: NTIS, TRIS, USDOT
  • Created Date: May 29 1975 12:00AM